/*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements.  See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership.  The ASF licenses this file

  * to you under the Apache License, Version 2.0 (the

  * "License"); you may not use this file except in compliance

  * with the License.  You may obtain a copy of the License at

  *

  *     http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing,

  * software distributed under the License is distributed on an

  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

  * KIND, either express or implied.  See the License for the

  * specific language governing permissions and limitations

  * under the License.

  */

 package org.apache.shiro.authc;

 /**

  * <p>A simple username/password authentication token to support the most widely-used authentication mechanism.  This

  * class also implements the {@link RememberMeAuthenticationToken RememberMeAuthenticationToken} interface to support

  * "Remember Me" services across user sessions as well as the

  * {@link org.apache.shiro.authc.HostAuthenticationToken HostAuthenticationToken} interface to retain the host name

  * or IP address location from where the authentication attempt is occuring.</p>

  * <p/>

  * <p>&quot;Remember Me&quot; authentications are disabled by default, but if the application developer wishes to allow

  * it for a login attempt, all that is necessary is to call {@link #setRememberMe setRememberMe(true)}.  If the underlying

  * <tt>SecurityManager</tt> implementation also supports <tt>RememberMe</tt> services, the user's identity will be

  * remembered across sessions.

  * <p/>

  * <p>Note that this class stores a password as a char[] instead of a String

  * (which may seem more logical).  This is because Strings are immutable and their

  * internal value cannot be overwritten - meaning even a nulled String instance might be accessible in memory at a later

  * time (e.g. memory dump).  This is not good for sensitive information such as passwords. For more information, see the

  * <a href="http://java.sun.com/j2se/1.5.0/docs/guide/security/jce/JCERefGuide.html#PBEEx">

  * Java Cryptography Extension Reference Guide</a>.</p>

  * <p/>

  * <p>To avoid this possibility of later memory access, the application developer should always call

  * {@link #clear() clear()} after using the token to perform a login attempt.</p>

  *

  * @since 0.1

  */

 public class UsernamePasswordToken implements HostAuthenticationToken, RememberMeAuthenticationToken {

     /*--------------------------------------------

     |             C O N S T A N T S             |

     ============================================*/

     /*--------------------------------------------

     |    I N S T A N C E   V A R I A B L E S    |

     ============================================*/

     /**

      * The username

      */

     private String username;

     /**

      * The password, in char[] format

      */

     private char[] password;

     /**

      * Whether or not 'rememberMe' should be enabled for the corresponding login attempt;

      * default is <code>false</code>

      */

     private boolean rememberMe = false;

     /**

      * The location from where the login attempt occurs, or <code>null</code> if not known or explicitly

      * omitted.

      */

     private String host;

     /*--------------------------------------------

     |         C O N S T R U C T O R S           |

     ============================================*/

     /**

      * JavaBeans compatible no-arg constructor.

      */

     public UsernamePasswordToken() {

     }

     /**

      * Constructs a new UsernamePasswordToken encapsulating the username and password submitted

      * during an authentication attempt, with a <tt>null</tt> {@link #getHost() host} and a

      * <tt>rememberMe</tt> default of <tt>false</tt>.

      *

      * @param username the username submitted for authentication

      * @param password the password character array submitted for authentication

      */

     public UsernamePasswordToken(final String username, final char[] password) {

         this(username, password, false, null);

     }

     /**

      * Constructs a new UsernamePasswordToken encapsulating the username and password submitted

      * during an authentication attempt, with a <tt>null</tt> {@link #getHost() host} and

      * a <tt>rememberMe</tt> default of <tt>false</tt>

      * <p/>

      * <p>This is a convience constructor and maintains the password internally via a character

      * array, i.e. <tt>password.toCharArray();</tt>.  Note that storing a password as a String

      * in your code could have possible security implications as noted in the class JavaDoc.</p>

      *

      * @param username the username submitted for authentication

      * @param password the password string submitted for authentication

      */

     public UsernamePasswordToken(final String username, final String password) {

         this(username, password != null ? password.toCharArray() : null, false, null);

     }

     /**

      * Constructs a new UsernamePasswordToken encapsulating the username and password submitted, the

      * inetAddress from where the attempt is occurring, and a default <tt>rememberMe</tt> value of <tt>false</tt>

      *

      * @param username the username submitted for authentication

      * @param password the password string submitted for authentication

      * @param host     the host name or IP string from where the attempt is occuring

      * @since 0.2

      */

     public UsernamePasswordToken(final String username, final char[] password, final String host) {

         this(username, password, false, host);

     }

     /**

      * Constructs a new UsernamePasswordToken encapsulating the username and password submitted, the

      * inetAddress from where the attempt is occurring, and a default <tt>rememberMe</tt> value of <tt>false</tt>

      * <p/>

      * <p>This is a convience constructor and maintains the password internally via a character

      * array, i.e. <tt>password.toCharArray();</tt>.  Note that storing a password as a String

      * in your code could have possible security implications as noted in the class JavaDoc.</p>

      *

      * @param username the username submitted for authentication

      * @param password the password string submitted for authentication

      * @param host     the host name or IP string from where the attempt is occuring

      * @since 1.0

      */

     public UsernamePasswordToken(final String username, final String password, final String host) {

         this(username, password != null ? password.toCharArray() : null, false, host);

     }

     /**

      * Constructs a new UsernamePasswordToken encapsulating the username and password submitted, as well as if the user

      * wishes their identity to be remembered across sessions.

      *

      * @param username   the username submitted for authentication

      * @param password   the password string submitted for authentication

      * @param rememberMe if the user wishes their identity to be remembered across sessions

      * @since 0.9

      */

     public UsernamePasswordToken(final String username, final char[] password, final boolean rememberMe) {

         this(username, password, rememberMe, null);

     }

     /**

      * Constructs a new UsernamePasswordToken encapsulating the username and password submitted, as well as if the user

      * wishes their identity to be remembered across sessions.

      * <p/>

      * <p>This is a convience constructor and maintains the password internally via a character

      * array, i.e. <tt>password.toCharArray();</tt>.  Note that storing a password as a String

      * in your code could have possible security implications as noted in the class JavaDoc.</p>

      *

      * @param username   the username submitted for authentication

      * @param password   the password string submitted for authentication

      * @param rememberMe if the user wishes their identity to be remembered across sessions

      * @since 0.9

      */

     public UsernamePasswordToken(final String username, final String password, final boolean rememberMe) {

         this(username, password != null ? password.toCharArray() : null, rememberMe, null);

     }

     /**

      * Constructs a new UsernamePasswordToken encapsulating the username and password submitted, if the user

      * wishes their identity to be remembered across sessions, and the inetAddress from where the attempt is ocurring.

      *

      * @param username   the username submitted for authentication

      * @param password   the password character array submitted for authentication

      * @param rememberMe if the user wishes their identity to be remembered across sessions

      * @param host       the host name or IP string from where the attempt is occuring

      * @since 1.0

      */

     public UsernamePasswordToken(final String username, final char[] password,

                                  final boolean rememberMe, final String host) {

         this.username = username;

         this.password = password;

         this.rememberMe = rememberMe;

         this.host = host;

     }

     /**

      * Constructs a new UsernamePasswordToken encapsulating the username and password submitted, if the user

      * wishes their identity to be remembered across sessions, and the inetAddress from where the attempt is ocurring.

      * <p/>

      * <p>This is a convience constructor and maintains the password internally via a character

      * array, i.e. <tt>password.toCharArray();</tt>.  Note that storing a password as a String

      * in your code could have possible security implications as noted in the class JavaDoc.</p>

      *

      * @param username   the username submitted for authentication

      * @param password   the password string submitted for authentication

      * @param rememberMe if the user wishes their identity to be remembered across sessions

      * @param host       the host name or IP string from where the attempt is occuring

      * @since 1.0

      */

     public UsernamePasswordToken(final String username, final String password,

                                  final boolean rememberMe, final String host) {

         this(username, password != null ? password.toCharArray() : null, rememberMe, host);

     }

     /*--------------------------------------------

     |  A C C E S S O R S / M O D I F I E R S    |

     ============================================*/

     /**

      * Returns the username submitted during an authentication attempt.

      *

      * @return the username submitted during an authentication attempt.

      */

     public String getUsername() {

         return username;

     }

     /**

      * Sets the username for submission during an authentication attempt.

      *

      * @param username the username to be used for submission during an authentication attempt.

      */

     public void setUsername(String username) {

         this.username = username;

     }

     /**

      * Returns the password submitted during an authentication attempt as a character array.

      *

      * @return the password submitted during an authentication attempt as a character array.

      */

     public char[] getPassword() {

         return password;

     }

     /**

      * Sets the password for submission during an authentication attempt.

      *

      * @param password the password to be used for submission during an authentication attemp.

      */

     public void setPassword(char[] password) {

         this.password = password;

     }

     /**

      * Simply returns {@link #getUsername() getUsername()}.

      *

      * @return the {@link #getUsername() username}.

      * @see org.apache.shiro.authc.AuthenticationToken#getPrincipal()

      */

     public Object getPrincipal() {

         return getUsername();

     }

     /**

      * Returns the {@link #getPassword() password} char array.

      *

      * @return the {@link #getPassword() password} char array.

      * @see org.apache.shiro.authc.AuthenticationToken#getCredentials()

      */

     public Object getCredentials() {

         return getPassword();

     }

     /**

      * Returns the host name or IP string from where the authentication attempt occurs.  May be <tt>null</tt> if the

      * host name/IP is unknown or explicitly omitted.  It is up to the Authenticator implementation processing this

      * token if an authentication attempt without a host is valid or not.

      * <p/>

      * <p>(Shiro's default Authenticator allows <tt>null</tt> hosts to support localhost and proxy server environments).</p>

      *

      * @return the host from where the authentication attempt occurs, or <tt>null</tt> if it is unknown or

      *         explicitly omitted.

      * @since 1.0

      */

     public String getHost() {

         return host;

     }

     /**

      * Sets the host name or IP string from where the authentication attempt occurs.  It is up to the Authenticator

      * implementation processing this token if an authentication attempt without a host is valid or not.

      * <p/>

      * <p>(Shiro's default Authenticator

      * allows <tt>null</tt> hosts to allow localhost and proxy server environments).</p>

      *

      * @param host the host name or IP string from where the attempt is occuring

      * @since 1.0

      */

     public void setHost(String host) {

         this.host = host;

     }

     /**

      * Returns <tt>true</tt> if the submitting user wishes their identity (principal(s)) to be remembered

      * across sessions, <tt>false</tt> otherwise.  Unless overridden, this value is <tt>false</tt> by default.

      *

      * @return <tt>true</tt> if the submitting user wishes their identity (principal(s)) to be remembered

      *         across sessions, <tt>false</tt> otherwise (<tt>false</tt> by default).

      * @since 0.9

      */

     public boolean isRememberMe() {

         return rememberMe;

     }

     /**

      * Sets if the submitting user wishes their identity (pricipal(s)) to be remembered across sessions.  Unless

      * overridden, the default value is <tt>false</tt>, indicating <em>not</em> to be remembered across sessions.

      *

      * @param rememberMe value inidicating if the user wishes their identity (principal(s)) to be remembered across

      *                   sessions.

      * @since 0.9

      */

     public void setRememberMe(boolean rememberMe) {

         this.rememberMe = rememberMe;

     }

     /*--------------------------------------------

     |               M E T H O D S               |

     ============================================*/

     /**

      * Clears out (nulls) the username, password, rememberMe, and inetAddress.  The password bytes are explicitly set to

      * <tt>0x00</tt> before nulling to eliminate the possibility of memory access at a later time.

      */

     public void clear() {

         this.username = null;

         this.host = null;

         this.rememberMe = false;

         if (this.password != null) {

             for (int i = 0; i < password.length; i++) {

                 this.password[i] = 0x00;

             }

             this.password = null;

         }

     }

     /**

      * Returns the String representation.  It does not include the password in the resulting

      * string for security reasons to prevent accidentially printing out a password

      * that might be widely viewable).

      *

      * @return the String representation of the <tt>UsernamePasswordToken</tt>, omitting

      *         the password.

      */

     public String toString() {

         StringBuilder sb = new StringBuilder();

         sb.append(getClass().getName());

         sb.append(" - ");

         sb.append(username);

         sb.append(", rememberMe=").append(rememberMe);

         if (host != null) {

             sb.append(" (").append(host).append(")");

         }

         return sb.toString();

     }

 }